Add docs for ContentFilter class.

src/main/java/com/onarandombox/MultiverseCore/displaytools/ContentFilter.java

@@ -9,7 +9,11 @@ import java.util.regex.Pattern;
 import java.util.regex.PatternSyntaxException;
 
 /**
- * Filter content and text based on regex.
+ * <p>Filter content and text based on regex matching.</p>
+ *
+ * <p>Compile regex pattern based on {@link ContentFilter#filterString}. When prefixed with 'r=',
+ * use {@link ContentFilter#filterString} as the full regex pattern. Else, set to any match that
+ * contains the {@link ContentFilter#filterString}.<p>
  */
 public class ContentFilter {
 
@@ -20,13 +24,20 @@ public class ContentFilter {
     private Pattern filterPattern;
     private boolean exactMatch;
 
-    public ContentFilter() {
+    private ContentFilter() {
     }
 
+    /**
+     * @param filterString  The text to do matching, either plaintext or regex.
+     */
     public ContentFilter(@NotNull String filterString) {
         this(filterString, false);
     }
 
+    /**
+     * @param filterString  The text to do matching, else plaintext or regex.
+     * @param exactMatch    Should check for exact match when doing regex matching.
+     */
     public ContentFilter(@NotNull String filterString,
                          boolean exactMatch) {
 
@@ -35,11 +46,6 @@ public class ContentFilter {
         parseFilter();
     }
 
-    /**
-     * Compile regex pattern based on {@link ContentFilter#filterString}.
-     * When prefixed with 'r=', use {@link ContentFilter#filterString} as the full regex pattern.
-     * Else, set to any match that contains the {@link ContentFilter#filterString}.
-     */
     private void parseFilter() {
         if (filterString == null) {
             return;
@@ -54,6 +60,8 @@ public class ContentFilter {
 
     /**
      * Compile and store the regex into a {@link Pattern}.
+     *
+     * @param regex The regex text.
      */
     private void convertToMatcher(@NotNull String regex) {
         try {
@@ -84,22 +92,43 @@ public class ContentFilter {
                 : filterPattern.matcher((CharSequence) text).find();
     }
 
+    /**
+     * Checks if a filter string is present.
+     *
+     * @return True if there is a filter string, else false.
+     */
     public boolean hasFilter() {
         return filterString != null;
     }
 
+    /**
+     * Checks if regex pattern syntax is valid.
+     *
+     * @return True if valid, else false.
+     */
     public boolean hasValidPattern() {
         return filterPattern != null;
     }
 
-    public @Nullable String getString() {
+    /**
+     * @return The filter string.
+     */
+    @Nullable
+    public String getString() {
         return filterString;
     }
 
-    public @Nullable Pattern getPattern() {
+    /**
+     * @return The regex pattern.
+     */
+    @Nullable
+    public Pattern getPattern() {
         return filterPattern;
     }
 
+    /**
+     * @return True if filter is set to do exact matching, else false.
+     */
     public boolean isExactMatch() {
         return exactMatch;
     }
@@ -107,7 +136,7 @@ public class ContentFilter {
     /**
      * Nicely format the filter string to be used for showing the sender.
      *
-     * @return formatted filter string.
+     * @return The formatted filter string.
      */
     public @NotNull String getFormattedString() {
         return String.format("%sFilter: '%s'%s", ChatColor.ITALIC, filterString, ChatColor.RESET);